Manitowoc Ice MARINE MODEL S1800 - Manual (Page 78)

Refrigeration System Section 7
7-12
Part Number 80-1634-3
ANALYZING DISCHARGE PRESSURE
DURING FREEZE OR HARVEST CYCLE
Procedure
1. Determine the ice machine operating conditions:
Air temp. entering condenser ______
Air temp. around ice machine ______
Water temp. entering sump trough ______
2. Refer to Operating Pressure Chart for ice machine
being checked.
Use the operating conditions determined in step 1 to
find the published normal discharge pressures.
Freeze Cycle _______ Harvest Cycle _______
3. Perform an actual discharge pressure check.
4. Compare the actual discharge pressure (step 3) with
the published discharge pressure (step 2).
The discharge pressure is normal when the actual
pressure falls within the published pressure range for the
ice machine’s operating conditions.
Freeze Cycle Discharge Pressure High Checklist
Freeze Cycle Discharge Pressure Low Checklist
NOTE: Do not limit your diagnosis to only the items listed in the checklists.
Freeze Cycle
PSIG (kPa)
Harvest Cycle
PSIG (kPa)
Beginning of Cycle __________ __________
Middle of Cycle __________ __________
End of Cycle __________ __________
Possible Cause Check/Correct
Improper installation See “Installation/Visual Inspection Checklist”
Restricted condenser water flow Low water pressure [20 psi (138 kPa) min.]
High inlet water temperature (90°F/32.2°C max.)
Dirty condenser
Dirty/defective water regulating valve
Water regulating valve out of adjustment
Improper refrigerant charge Overcharged
Non-condensables in system
Wrong type of refrigerant
Other Non-Manitowoc components in system
High side refrigerant lines/component restricted (before mid-condenser)
Possible Cause Check/Correct
Improper installation See “Installation/Visual Inspection Checklist”
Improper refrigerant charge Undercharged
Wrong type of refrigerant
Water regulating valve Out of adjustment
Defective
Other Non-Manitowoc components in system